Gantt charts illustrate start dates and finish dates of elements of a project. An element of a project can correspond to a task or an activity of the project, for example. The Gantt chart of a project can show the dependency relationships that exist between the elements of the project. Different kinds of dependency relationships between elements can include finish-to-start, finish-to-finish, start-to-start, and start-to-finish.
In a finish-to-start relationship, a second element does not start before a first element is finished. In a finish-to-finish relationship, the second element does not finish before the first element is finished. In a start-to-start relationship, the second element does not start before the first element starts. Finally, in a start-to-finish relationship, the second element does not finish before the first element starts.